Lymphocytic choriomeningitis virus and Tacaribe virus (another arenavirus) have been found to produce a destructive retinopathy following intracerebral inoculation in the neonatal rat. These lesions are immunologically mediated as indicated by the sparing effects of antilymphocyte serum. These models, delineated by prior work in this laboratory, provide a superb opportunity to study in detail a prototype of virus-induced retinal immunopathology. It is now proposed to exploit these models to pursue several long term goals: to establish other animals of virus-induced ocular disease; to clarify the pathogenetic mechanisms which contribute to the development of viral retinopathy; and to dissect the intimate immunological and pathological mechanisms which mediate these diseases using current techniques of cellular immunology.